Copperwheat, C.M., Marsh, T.R., Dhillon, V.S. orcid.org/0000-0003-4236-9642 et al. (4 more authors) (2010) Physical properties of IP Pegasi: an eclipsing dwarf nova with an unusually cool white dwarf. Monthly Notices of the Royal Astronomical Society , 402. pp. 1824-1840. ISSN 0035-8711
Abstract
We present high-speed photometric observations of the eclipsing dwarf nova IP Pegasi (IP Peg) taken with the triple-beam camera ULTRACAM mounted on the William Herschel Telescope. The primary eclipse in this system was observed twice in 2004, and then a further 16 times over a 3 week period in 2005. Our observations were simultaneous in the Sloan u′, g′ and r′ bands. By phase-folding and averaging our data, we make the first significant detection of the white dwarf ingress in this system and find the phase width φ of the white dwarf eclipse to be 0.0935 ± 0.0003, significantly higher than the previous best value of 0.0863 < φ < 0.0918. The mass ratio is found to be q=M2/M1= 0.48 ± 0.01, consistent with previous measurements, but we find the inclination to be forumla, significantly higher than previously reported. We find the radius of the white dwarf to be 0.0063 ± 0.0003 R⊙, implying a white dwarf mass of 1.16 ± 0.02 M⊙. The donor mass is 0.55 ± 0.02 M⊙. The white dwarf temperature is more difficult to determine, since the white dwarf is seen to vary significantly in flux, even between consecutive eclipses. This is seen particularly in the u′ band, and is probably the result of absorption by disc material. Our best estimate of the temperature is 10 000–15 000 K, which is much lower than would be expected for a cataclysmic variable star with this period, and implies a mean accretion rate of <5 × 10−11 M⊙ yr−1, more than 40 times lower than the expected rate.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2010 The Authors. Journal compilation © 2010 RAS Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 06 Nov 2017 16:10 |
Last Modified: | 06 Nov 2017 16:10 |
Published Version: | https://doi.org/10.1111/j.1365-2966.2009.16010.x |
Status: | Published |
Publisher: | Oxford University Press |
Refereed: | Yes |
Identification Number: | 10.1111/j.1365-2966.2009.16010.x |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:123563 |